Tamper proof throttle valve



July 6, 1965 s. F. ELSTON ETAL TAMPER PROOF THROTTLE VALVE Original Filed June 9, 1958 k I42 FIG S E A 4 M v M S O G T. T I WSBJ T F 1LT A E E F. C EDW W M L U/ G FIG 3 United States Patfiirlt O 3,192,547 TAMPER PRQDF THRGTTLE VALVE George F. Elston, Birmingham, and Gerald F. Tess, Roseville, Mich, and Laurence 5. Evans, Denver, (30210., assignors to Sperry Rand Corporation, a corporation of Delaware Original application June 9, 1958, Ser. No. 749,803, now Patent No. 3,082,787, dated Mar. 26, 1953. fiividerl and this application Sept. 13, I962, Ser. No. 232,632 4 Claims. (Cl. 137385) The present application constitutes a division of the application of George F. 'Elston, Gerald F. Tess, and Laurence J. Evans, filed under Serial No. 740,803 on June 9, 1958, which became Patent No. 3,082,787 on March 26, 1963. r

This invention relates to power transmissions, and is particularly applicable to those of the type comprising two or more fluid pressure energy translating devices, one of which may function as a pump and another as a fluid motor.

More particularly the invention is concerned with an improved flow regulating valve. Flow regulating valves have an important use in hydraulic power transmission systems, such as in systems for driving machine tools wherein they serve to accurately regulate the speed of a fluid motor for driving the machine tool and to maintain such speed constant.

One type of flow regulating valve in common use ha incorporated therein an adjustable throttle and a pressure compensating valve. The compensating valve is responsive .to pressure changes ahead of or beyond the throttle for maintaining a substantially constant pressure drop across the throttle and thus the flow therethrough at a constant rate for any given setting of the throttle.

One disadvantage of prior flow regulating valves has been the lack of tamper-proof means for preventing the changing of carefully preselected throttle settings. The throttle setting to give a particular feed rate of a machine tool is carefully calculated, not only to provide a good grade of finished product, but also toconserve tool life. However, some operators of machine tools for various reasons will adjust the throttle setting to increase the feed rate of the machine tool beyond recommended limits, and in many cases the cut-ting tool is ruined.

It is, therefore, an object of this invention to provide an improved flow regulating valve with features alleviat-ing the disadvantage previously recited.

It is still another object of this invention to provide an improved flow regulating valve having an adjustable throttle, which can be locked to a desired setting.

It is still another object of this invention to provide an improved flow regulating valve having a dial operated throttle for adjusting the opening of the throttle, the dial of which can be locked to a desired tampe-rproof setting.

It is still another object of this invention to provide an improved flow regulating valve which is simple in construction, efiicient in operation and which is relatively inexpensive to manufacture.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred form of the present invention is clearly shown.

In the drawing:

FIGURE 1 is a front elevation view, partially in section, of a preferred form of the present invention.

FIGURE 2 is .a sectional view taken on line 22 of FIGURE 1.

FIGURE 3 is a partial, sectional view taken on line 3 of FIGURE 1.

FIGURE 4 is a partial, sectional view taken on line 44 of FIGURE 1.

Referring now to FIGURES 1 and 2 of the drawings, there is illustrated a flow regulating valve, indicated gen: erally by the numeral 10, comprising a body .12 having mounted therein a throttle valve 16 comprising a hollow piston, which is in series with a pressure compensating valve, the structure and operation of which is described in detail in our Patent No. 3,082,787.

The throttle valve 16 is shiftably mounted in a throttle bore 20 which extends completely through the body 12 from the front to the rear thereof. The bore 20 is closed at the rear of the body by a threaded closure member 22, and at the front face of the body by a throttle adjusting screw member 24 threaded into the throttle bore at 25. The screw member 24 is keyed to an insert member 26 threaded into a dial 28 and locked thereto by a set screw 29. The end of the screw member is free to slide in the insert member 26, and an end clearance is provided between the screw member and dial for that purpose.

A rod member 30 extends into a bore 32 of the adjusting member 24 with an end surface 34 of the rod adapted to abut a surface 36 forming the closed end of bore 32. The opposite end of the rod 30, which is indicated by the numeral 38, extends through a hole-40 formed in the closed end 42, of the throttle valve 16 into the hollow portion thereof and slightly beyond, where it is exposed to flow through a throttle chamber 44 formed in the throttle bore 20 between the open end of the throttle valve 16 and closure member 22.

The rod 30 is provided with a flange'forming a seat 46 upon which the closed end surface 42 of the throttle valve 16 rests so that when the adjusting member 24 is screwed inwardly the throttle valve 16 is moved inwardly into the bore 29 against the bias of a spring 48 adapted to resiliently load the throttle valve 16 against the seat 46. The spring 43 is mounted in the throttle chamber 44 and extends into the hollow portion of the throttle valve 16. When the adjusting member is screwed outwardly, the spring 48 will shift the throttle valve 16 to a new adjusted throttle setting, the rod member also being shifited with the throttle valve; 7

A plurality of holes 45 are constructed through the closed end of the throttle valve 16 for connecting the throttle chamber 44 to a chamber 47 formed in the bore 20 between the throttle valve 16 and the adjusting member 24. A portion 49 of the rod 30, located in the chamber 47, is thus also exposed to fluid, the temperature of which changes with that flowing through the inlet chamber 44. The rod is adapted to expand and contract in response to fluid temperature changes for changing the throttle setting. Reference may be madeto hereinbefore-mentioned Patent No. 3,082,787, which fully describes the metallic composition of theseveral components and the automatic temperature compensation features of the device.

Referring now to the flow passage construction of the device, inlet and outlet external connection ports 53 and 51, respectively, are formed in the rear surface 55 of the body 12. Inlet flow to the external inlet connection port 53 is adapted to be conducted by an inlet passage to a branch inlet passage leading to the compensating valve.

Another branch inlet passage 62 leads from the compensating valve to the downstream throttle chamber 44 formed in throttle bore 20. Passage 62 opens laterally or transversely tothe throttle chamber 44 and is con: trolled by throttle valve 16, said opening being indicated in FIGURE 2 by the numeral 64. A sharp edged orifice is thus formed by the leading edge of throttle valve 16 and the edge of the Wall opening to the throttle bore. An outlet passage 66, offset from passage 62, leads from the side of throttle chamber 44 to a branchoutlet passage 68 leading to the external connection outlet port 51 in face 55 of the body 12.

Forthe purpose of providing unregulated reverse flow from the outlet passage .to the inlet passage, a branch passage is provided which connects the outlet port 51 and outlet passage 68 to a passage leading to a check valve, not shown. 7

Referring now to the throttle dial and locking arrangement therefor, the body 12 is provided with a stepped bore 94- extending from the front face 96 of the body and within which is mounted an under portion $8 of the dial having a flange 100 adapted to rest on a shoulder 102 of the stepped bore. A cover plate 164, which is maintained on the front face 96 of the body 12 by screws 106, is centrally perforated, indicated by the numeral 107 in FIG- URE 1, so that the dial may extend therethrough and so that the surface area of the plate immediately surrounding the perforation covers the flange and prevents the dial from lifting from the body.

The locking arrangement comprises a pawl 10 8 mounted in a milled-out portion 110 in the front of the body and which is provided with serrations 112 at its inner end. The pawl is adapted to be shifted into engagement with mating serrations 114 located on the under portion of the dial, after proper adjustment of the throttle has been made and then locked to prevent rotation of the dial. For this purpose an inner angular surface 116 of the pawl, opposite the serrated end of the pawl, is engaged by a tapered portion 118 of a locking screw 120, shown in FIGURE 4, which when threaded into the body forces the pawl against the dial serrations by a wed ging action. The head 122 of the screw may be engaged, for unlocking and locking the pawl, through an access hole 124 formed in theplate. When a throttle adjustment is to be made the screw 129 is partially withdrawn and the pawl 108 drops permitting the mating pawl and dial serrations to disengage to permit rotation of the dial for adjusting the throttle. A clearance, indicated by the numeral 125, is provided between the inner end of the pawl and the screw, permitting the pawl to drop and thus disengage the mating serrations.

In order to prevent tampering with the locking screw and thus permit changing of carefully preselected throttle settings, the access hole 124 is closed by an end portion 126 of an arm 128, rotatable to and locked in the closed position as shown in dotted lines in FIGURE 1 by means of a cylinder 130 of a lock assembly 132 rotatably mounted in a stepped bore 134 extending completely through the body from front to rear thereof. The lock assembly is maintained in the bore 134 by means of a head 135 of a screw 137 threaded into the cylinder which is adapted to loosely abut a shoulder 139 of the stepped bore and by cooperating shoulders formed in the stepped bore and on the cylinder. The arm 128 is mounted in a recessed portion 136 in the front of the body and may be fastened to the cylinder in any suitable manner, such as by being keyed to a slot in the head end of the cylinder, indicated generally by the numeral 141 in FIGURE 2, so as to be rotatable by the cylinder 130. The cylinder 130 in the locked position is prevented from rotation by a plurality of spring pressed plungers or tumblers 138, shown in FIGURE 2, which for the purposes of illustration have been shown in the extended position. The plungers extend into an offset drilled hole 133 of bore 134 also shown in FIGURE 1 to prevent dial rotation. It should be understood, however, that when a key 1413 is inserted in a keyhole slot 142 of the lock, the plungers are released.

With the key inserted in the keyhole slot 142, the plungers 138 are released from the hole 133 and turning of the key rotates the cylinder, which in turn rotates the arm 128 so that the arm portion 126 uncovers the access hole 124. In order to prevent lifting of the dial by removal of the cover plate so that access can be had to the adjusting member 24, the outer periphery 144 of the proease? 1 jecting portion 126 of the arm 128. fits into a groove 146 located in the under portion of the dial directly beneath the flange and prevents lifting of the dial (FIGURES 2 and 4). The cylinder must first be rotated to shift the outer periphery 144 of the arm portion 126 from the groove 146 before the'dial can be lifted.

Referring now to the improved dial throttle indicia arrangement for properly indicating the adjustment setting of the throttle, the outer face of the dial flange 1410 is provided with numerals from 0-9 with line markings inbetween, some of which appear through an arcuately shaped cutout portion 148 of the plate below a centrally located indicating arrow 150 on the outer surface of the plate.

The adjusting member 24 has to be completely rotated in the threaded portion of its body mounting bore several times in order to permit the throttle to shift axially from the 0 or closed position to its maximum throttle opening. Thus, in the device disclosed which is designed for a maximum rating of 1000 cubic inches per minute, it would take about 3.3 turns of the adjusting member to obtain 1000 cubic inches or approximately 0.85 cubic inch per each degree of rotation. For the purpose of indicating the number of turns of the adjusting member, a small rotor 152 is provided with letters thereon. The rotor 152 is rotatably mounted in a recess 154 in the front face of the body 12 and is free to slide slightly vertically toward the dial flange, being biased in that direction by a spring 156 (FIGURES l and 3). A plurality of spaced apart teeth 158 extend from the rotor which are adapted to successively engage a groove 160 in the flange. As the dial is turned, the rotor will be turned and a letter indicating the number of turns of the dial will appear through a hole 162 in the plate. Thus, the letter B represents one complete turn of the dial, which together with the numeral markings previously explained, will indicate a particular opening of the throttle to provide a predetermined fiow rate. The letter C indicates two complete turns of the dial, which together with the numerals appearing through the arcuate slot would indicate another more fully open setting of the throttle with a higher flow rate. When the rotor is turned to a setting C, for example, and the dial is continued to be rotated, the tooth responsible for the actuation of the rotor, which had been impressed in the groove 160, will ride out of the groove on top of the flange. The rotor will not be actuated again until another complete turn of the dial has been made, at which time the next adjacent tooth will be pressed into the groove 160 to rotate the rotor for bringing the next letter into view through the sight hole 162 to indicate a still more fully opened setting of the throttle.

In summary, there is thus provided a tamper-proof locking of the throttle setting through the medium of the locking pawl 108, which can only be released from its locked position with the dial serrations 114 by means of locking screw 120. Access to the locking screw 120 can only be had through the access hole 124 in the plate 104 which, once the throttle has been adjusted, is covered by an end portion 126 of the arm 128 which is locked to a position closing the access hole by lock assembly 132. A special key 140 must first be inserted in the keyhole slot 142 of cylinder 139 to release the tumblers 138 from the drilled hole 133, which will unlock the cylinder to permit rotation of the same and thus rotation of the arm 128 to uncover the access hole. Removal of the plate 104 will not provide access to the locking screw 120 because the arm portion 126 is locked to a position over the screw.

Removal of the plate 104 from the ront of the body will not permit access to the screw member 144 for adjusting the throttle because the dial must first have to be lifted from the adjusting screw 144 and removal of the dial from the body is prevented by the expedient of having the peripheral portion 144 of the arm portion 126 rest in the groove 146 below the flange 100 of the dial. The arm portion 126 must first be rotated away from the dial to remove the peripheral portion thereof from the groove and as previously recited, the arm is locked by the lock assembly to this position.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming Within the scope of the claims which follow.

What is claimed is as follows:

It. In a flow regulating valve for use in a hydraulic power transmission system, a body member having a flowv passage extending therethrough, a resiliently biased throttle valve extending into said flow passage for restricting the flow therethrough, means for adjusting the position of the throttle valve in the passage, means shiftably mounted in the body engageable With the adjusting means to maintain the throttle in adjusted position, manually operable means for actuating the shittable means engageable for operation through an access aperture, manually operable aperture control means for opening and closing the aperture comprising a cylinder rotatably mounted in the body, an arm member rotatable by said cylinder to close and open the access aperture, and a key member insertable in said cylinder for rotating the cylinder.

2. In a flow regulating valve for use in a hydraulic power transmission system, a body member having a flow passage extending therethrough, a resiliently biased throttle valve extending into said flow passage for restn'cting the flow therethrough, means for adjusting the position of the throttle valve in the passage, means shiftably mounted in the body engageable with the adjusting means to maintain the throttle in adjusted position, manually operable means for actuating the shittable means valve extending into said flow passage for restricting the flow therethrough, means for adjusting the position of the throttle valve in the passage, 21 bore in said body having an access opening on a surface of said body, means for locking said adjusting means which is engageahie through said bore, a plate member shift-able on said surface of the body over the bore opening for controlling access to the adjustable locking means, a manually operable actuating means in said body associated with the plate member and including locking means, said actuating means having a key slot accessible from said surface of the body, and a key member insertable'in said slot for both unlocking and manually operating said plate member actuating means. 7

4. In a flow regulator valve for use in a hydraulic power transmission system, a body member having a flow passage extending therethrough, a resiliently biased throt tle'valve extending into, said flow passage for restricting the flow therethrough, means for adjusting the position of the throttle valve in the passage, a bore in said body having an access opening on a surface of said body, means for locking said adjusting means which is engageable associated with said plate member rotatably mounted in engageable for operation through an access aperture, 1

3. In a flow regulator valve for use in a hydraulic power transmission system, a body member having a flow pas sage extending therethrough, a resiliently biased throttle the body and including spring biased locking means, said actuating means having a key slot accessible fromsaid surface of the body, and a key member insertable in said slot for unlocking said actuating means and for manually rotating said actuating means to shift said plate from the bore opening to provide access to the adjustable locking means.

References Cited by the Examiner UNITED STATES PATENTS 450,451 4/91 Ferrell 137-553 XR 1,147,634 7/15 Lotz l37383XR 1,231,164 6/17 Jahns 137 3s4 FOREIGN PATENTS 521,519 1921 France.

ISADOR WEIL, Primary'Examiner. 

1. IN A FLOW REGULATING VALVE FOR USE IN A HYDRAULIC POWER TRANSMISSION SYSTEM, A BODY MEMBER HAVING A FLOW PASSAGE EXTENDING THERETHROUGH, A RESILIENTLY BIASED THROTTLE VALVE EXTENDING INTO SAID FLOW PASSAGE FOR RESTRICTING THE FLOW THERETHROUGH, MEANS FOR ADJUSTING THE POSITION OF THE THROTTLE VALVE IN THE PASSAGE, MEANS SHIFTABLY MOUNTED IN THE BODY ENGAGEABLE WITH THE ADJUSTING MEANS TO MAINTAIN THE THROTTLE IN ADJUSTED POSITION, MANUALLY OPERABLE MEANS FOR ACTUATING THE SHIFTABLE MEANS ENGAGEABLE FOR OPERATION THROUGH AN ACCESS APERTURE, MANUALLY OPERABLE APERTURE CONTROL MEANS FOR OPENING AND CLOSING THE APERTURE COMPRISING A CYLINDRICAL ROTATABLY MOUNTED IN THE BODY, AN ARM MEMBER ROTATABLE BY SAID CYLINDER TO CLOSE AND OPEN THE ACCESS APERTURE, AND A KEY MEMBER INSERTABLE IN SAID CYLINDER FOR ROTATING THE CYLINDER. 